While playing the game and a level first starts, press R2, L2, Up, Down, X, L3, Circle, X, Circle, X.

All weapons in training level

Start the training level, then enable the "Level skip" code. You will complete it with a "Silent Assassin" rank. Choose the training level again, and all the weapons in the game will be unlocked in the weapons storage area. This also will unlock the Cardboard Tube weapon.

Second chance

When you are killed, the screen will turn black and white briefly. Try to shoot four people in the head while this is happening to resume playing with barely any health.

Bonus weapons

Successfully complete the indicated mission with a "Silent Assassin" rank to unlock the corresponding weapon:

CZ 2000 Dual Pistols: Mission 1

Micro Uzi Dual Submachine Guns: Mission 2

Silverballer Silenced Dual Pistols: Mission 3

Magnum 500 Dual Pistols: Mission 4

Sawed-Off Shotgun Dual: Mission 5

M4 Carbine Silenced Assault Rifle: Mission 6

SG220 .S Dual Pistols: Mission 7

MP5 Silenced Submachine Gun: Mission 8

AK 74 Silenced Assault Rifle: Mission 9

GK 17 Dual Pistols: Mission 10

Micro Uzi Silenced Dual Submachine Guns: Mission 11

PGM Silenced Sniper Rifle: Mission 12

Humorous translations in The Bjarkhov Bomb

Go inside of the submarine. There are some Russians wearing radiation suits working on the dirty bomb. The translation of what they are saying are the following four phrases:

"I hate this frozen wasteland."

"Careful! Are you trying to kill us?"

"Thank God there were 2 boxes of vodka on the plane this morning."

"Help me a little."

Phantom chef in The Seafood Massacre

Once the mission starts, run to the restaurant's basement where you cut the gas off. Grab the restaurant outfit and quickly run to kill the Red Dragon Negotiator. Dump him in the sewer, grab his amulet, and climb out. Next, head back to the basement. The guards will not know that you are not a restaurant employee. Cut the gas. Hide in the room where you got the outfit from and wait for the chef to go over to the gas thing. Quickly, yet quietly, exit the room and get behind the Chef. Note: Make sure you have the syringe out before you walk out the room. Just when he turns his head and spots you, stab him with the syringe. If done correctly, he should stand up and slowly walk away, leaving you in the motion as if you stabbed him. He will walk out the door, and get knocked out there.

Ghosts in Traditions Of The Trade

Once you enter the hotel, turn right to the double doors. Go through them and there will be another set of double doors. Pick them, as they are locked. After that, go down past two doors and look quickly because the ghost goes into the wall.

Follow the same instructions to see the ghost in the hallway for this level, then go into the room that the ghost enters. Kill the guard in the bathroom and look in the mirror. The reflection will show the ghost, but if you turn around nothing is there.

Look for the ghost in the hall where the murder took place. Go into a room and look into the mirror. You see the ghost floating behind you. You can see him in any room of that hall, and not just the one he walks into.

Bleeding ghost in Traditions Of The Trade

In the part where the ghost appears and goes into the room in the dark hallway, enter that room and go back into the shower. The ghost will appear by the back wall. If you shoot it, blood with splatter on the wall. If you missed him the first time, just leave the room then return and he will reappear. You can do this as many times as desired. When you shoot him, it will seem as if time slowed down and speeds back up.

Kill the Ghost in Traditions Of The Trade

Go down to the hallway at the bottom floor of the hotel. You will see the ghost that walks through into a wall. Move to a dead plant in the corner of the hallway near to a locked door. Then, go back towards the hallway where you saw the ghost. Make sure you have your Fibre Wire out before continuing. Heading down the corridor, you will see the ghost who walks into the wall. Get your Fibre Wire ready then get behind the ghost before it disappears into the wall. If you are quick, you can strangle the ghost with your Fibre Wire, which now flickers on the ground. You can now drag the ghost around the hotel.

See murder in Traditions Of The Trade

Go to your map in the level. There is a point of interest in the corner of the second or third floor. There is police tape and a guard there. Kill the guard, sneak in, and you will find a dead man on the bed. Go into the bathroom to see a bathtub full of blood. There is a sawedoff shotgun in front of it that can help you if you do not have any guns.